Wear an Atomic Clock on Your Wrist

Ever since their invention, "atomic clocks" have been the gold standard for timekeeping, deviating by less than a second every million or so years. Most are extremely large and require plenty of technical expertise to operate. Now, scientists at the National Institute for Standards and Technology -- the primary keepers of atomic clocks in the U.S. -- has developed a miniaturized atomic clock that could one day be incorporated into a wristwatch.

The NIST miniature atomic clock is accurate to within a second every 300 years -- not as impressive as its industrial-strength brethren, but hey... in 300 years, you'll probably want a new watch anyhow. It works through a tiny bit of cesium vapor trapped in silicon; the clock measures the oscillation of the cesium atoms to count off time.

You might not need a watch that's that precise, but one immediate application is in GPS systems, where time accuracy and synchronization are critical.